Heating furnace with skid rails



"United States Patent Charles Robert Wilt, Jr. Upper St. Clair,Pennsylvania 800,912

Feb. 19, 1969 Nov. 17, 1970 Salem-Broslus, Inc.

a corporation of Pennsylvania HEATING FURNACE WITH SKID RAILS 13 Claims,8 Drawing Figs.

US. Cl

lnventor Appl. No. Filed Patented Assignee FieldofSem-ch .11. 263/6, 6A,

[56] References Cited UNITED STATES PATENTS 1,922,888 8/1933 Engelbert:263/6 2,076,739 4/1937 Menough 263/6X 2,620,174 12/1952 Passafaro 263/6Primary Examiner-John J. Camby Attorney-Buell, Blenko & ZiesenheimABSTRACT: A furnace for heating metal objects such as slabs, blooms,beam blanks, or the like. The metal objects are pushed through thefurnace on water-cooied skids. Means are provided in the furnace fortransferring the metal objects from the water-cooled skids onto memberswhich support the metal objects when they are at rest during the finalheat cycle.

Patented Nov. 17, 1970 Sheet m2. of 5.

on v mm G G O Q G mw Q m mm mm hi5 ATTORNEYS Patented Nov. 17, 1970Sheet 3 of5 m T N E V m CHARLES R. WILT Jr.

Uni

his ATTORNEYS Patented Nov. 17, 1970 Sheet .1 w of 5 III F l I CHARLESR. WILTJr.

. s ,Y E m ,N R m m 3 m Yaw .5 in] B .n I I 1/ i o .o H a A 2 2040 w 2441.33% /4 II. I /1 l1 /i ll 6 A I I I I I "Q w 0 B Patented Nov. 17,1970 r 3,540,706

Sheet .'5 of 5 INVENTOR.

CHARLES R. WELT Jr.

iz Maw his ATTORNEYS HEATING FURNACE WITI-I SKID RAILSv This inventionrelates to a heating furnace, and particularly I to such a furnacehaving improvements in the means for supporting objects during the finalheating thereof.

One manner of heating metal slabs, blooms, beam blanks, and the like, iscontinuously heating them in familiar elongated furnaces. The workpieces are pushed into the furnace with conventional pushers and aresupported in the furnace on water-cooled skids in preheating and heatingzones. The work pieces are removed from the discharge end of the furnaceby an extractor or are removed by passing them through a conventionaldropout. A new piece is pushed in at the charge end of the furnace andall of the pieces in the furnace advance along its length with one piecebeing discharged from the furnacc. In the conventional furnace the workpieces are in contact with the skids until the pieces are urged into thesoaking zone located at the discharge end of the furnace. Skid marks areformed on the undersurface of the work pieces in contact with the skidsdue to the continuous removal of heat from the pieces by the waterflowing through the skids. These skid marks are removed from the workpieces by applying heat to the pieces in the soaking zone while thepieces rest on a solid refractory hearth. The work pieces are soaked byapplying heat to their top surfaces, which then soaks through the piecesto supply the heat necessary to eliminate the skid marks. This soakingrequires considerable time. Also, since the work pieces are pushedacross the solid refractory hearth, the hearth is subject toconsiderable refractory wear and as a result requires frequent timeconsuming maintenance.

I overcome the problems set forth above inherent in a solid refractoryhearth in the soaking zone of a continuous heating furnace. by providinga furnace which has a heating zone including water-cooled skids overwhich the work pieces can be pushed and multiple support membersdisposed between the skids and means for moving the support members orthe skids for transferring the work pieces from the skids to the supportmembers, whereby the skid marks are erased while the work pieces are onthe support members. By supporting the work pieces on the supportmembers heat can be supplied to both the top and bottom of the workpieces, and as a result, it will take less time for removal of skidmarksformed on the work pieces as compared with soaking the pieces on asolid hearth.

Furthermore, the additional heat supplied to the work pieces willshorten the time to obtain a uniform temperature of the work piecerequired for further working of the piece. In addition, the multiplesupport members of the furnace of my invention are not subject to thewear problems associated with the solid hearth since the work pieces arenot pushed along the support members but, rather, are pushed along theskids located in the final heating zone. In essence, what lam doing iseliminating the soaking zone of a continuous heating furnace and amproviding a final heating zone, so to speak. Thus, the furnace of myinvention also results in a furnace having a greater capacity togetherwith better uniformity of temperature of the work pieces heated therein,relative to a conventional heating furnace ofthe same length. Inaddition, as 'compared with the same conventional furnace, I can shortenthe length of my furnace and maintain equal capacity while providingbetter uniformity of temperature ofthe work pieces.

The principles of my present invention are also applicable to batch typeheating furnaces. There are batch type furnaces which have either asolid refractory hearth or piers upon which the work pieces rest whilebeing heated. I can provide a batch type furnace which will have themeans for transferring work pieces from one object support means toanother in accordance with the essence of the present invention. Thus,as compared to the conventional solid hearth or pier type batchfurnaces, my furnace will result in work pieces reaching betteruniformity of temperature in much shorter time, as well as eliminatingother well-known refractory hearth and pier problems.

More specifically, I provide a furnace having the advantages justenumerated, as well as others, comprising: an elongated generallyhorizontally oriented hollow housing defining a furnace chamber; burnermeans disposed in the housing for supplying hot products of combustioninto the furnace chamber to apply heat to the objects to be heated; aplurality of transversely spaced object support means supported inthehousing and extending throughout the length thereof for supportingobjects during heating; the object support means having firstmembers,.and second members disposed between the first members. with themembers being movable upwardly and downwardly with respect to eachother;and movable frame means operatively arranged with the object supportmeans for selectively tilting the members with respect to each other totransfer objects between the members.

Other details and advantages of the invention will become apparent asthe following description of certain present preferred embodimentsthereofproceed.

In the accompanying drawings I have shown certain present preferredembodiments ofthe invention in which: FIG. 1 is a vertical longitudinalsectional view through part ofa continuous heating furnace embodying thepresent inventiori, and showing the final heating zone of the furnacewith the work piece support members in one position;

FIG. 2 is a view similar to that of'FIG. 1 showing the work piecesupport members in a second position;

FIG. 3 is a fragmentary vertical transverse sectional view taken alongthe line 3-3 of FIG. 2;

- FIG. 4 is a schematic representation of the pattern of a troughforming part of seal means for the present invention;

FIG. 5 is a fragmentary vertical transverse sectional view similar tothat of FIG. 3 showing another arrangement of the work piece supportmembers in the final heating zone of a continuous furnace of the presentinvention;

FIG. 6 is a vertical longitudinal sectional view through part of acontinuous heating furnace embodying another form of the presentinvention, and showing the final heating zone of the furnace with thework piece support members in one position;

FIG.'7 is a similar view to that of FIG. 6 showing the work piecesupport members in a second position; and

FIG. 8 is a fragmentary vertical transverse sectional view taken alongthe line 8-8 of FIG. 6.

Referring now to the drawings wherein like reference numerals are usedto designate like parts throughout the various views, 10 is a heatingfurnace through which work pieces such as slabs I1, for example, passmore or less continuously to be heated. The basic structure ofthefurnace 10 includes an elongated housing 14 defining a furnace chamberhaving a preheating zone, not shown, a heating zone 16, part of which isshown, and a final heating zone 18 disposed inwardly of the dischargeend 20 of the furnace. Burners 22 are suitably arranged in the walls ofthe housing 14 for introducing into the furnace chamber hot products ofcombustion to apply heat to the slabs 11 passing therethrough. The slabs11 are passed through the furnace chamber by being pushed one againstthe other in any well-knownmanner, moving from left to right as viewedin FIGS. 1 and 2 The slabs 11 are supported in the preheating and bothheating zones on longitudinally extending, transversely spacedconventional water-cooled skids 24 suitably supported on platform 31. Ingeneral, except for the slab supporting means 30 in the final heatingzone 18, the furnace 10 may be more or less conventional and since suchfurnaces and their operation are well known to those skilled in the art,I shall not describe in any detail any portions of the furnace exceptthe structure of the support means 30.

Support means 30, asshown in FIGS. 1,2, and 3, includes a series ofelongated, transversely spaced platforms 32 which are part of theoverall platform 31, which platforms 32 are suitably supported on thefloor of the foundation for the furnace 10. A pair ofdownstream sections34 of the water-cooled skids 24 are supported by each of the platforms32 by U- shaped, transversely oriented, pipes 36 longitudinally spacedon platform 32. Each of the skids 24, including skid sections 34, isprovided over its entire longitudinal length with a conventional wearbar 35.

The object support means in the final heating zone 18 is movableupwardly and downwardly with respect to the skid sections 34. The objectsupport means include elongated pedestal members 40 disposed in thespaces between the platforms 32v The details of one pedestal member 40will be described with the understanding that the description pertainsto each of the pedestal-members shown in the drawings. Each pedestalmember 40 includes an upright tubular structure 42 formed in a fencelikepattern having a longitudinally extending upper section 43 and aplurality of vertical legs 44 joined to the upper section 43.-Uppersection 43 is formed with two vertical levels, a first level 43adisposed adjacent the heating zone 16 and a second level 43!; below thefirst level and forming the remainder of the upper section. Circulatingcooling water is passed through the tubular structure 42 and enters andleaves the vertical legs 44 by any suitable piping arrangement wellknown in the art. An elongated refractory cap 46 extends over the topsurface of the second level 43b of upper section 43 of tubular structure42. The refractory cap 46 is held fixed with respect to tubularstructure 42 by bracket 47 suitably secured to the upper section 43. Ashort wear bar 48 is suitably fixed to the top horizontal surface of thefirst level 43a of upper section 43.

Each pedestal member 40 is supported by an upright support structure 50which includes a pair of short pieces of transversely spaced firstI-beams 52 disposed adjacent the discharge end ofthe furnace in theexcavation 53 below the final heating zone 18. One each of a pair ofelongated second I-beams 54 is fixed to each of the first I-beams 52 andextend from the first I-beams-to a vertical plane passing through anintermediate region of the heating zone 16. Pairs of short sections offirst channels 56 are disposed at longitudinal intervals between thesecond I'-beams 54 and third I-beams 58. As shown in FIGS. 1 and 2, fourpairs of first channels 56 are disposed as described. The third I-beams58 extend in excavation 53 from adjacent the region of discharge end 20of the furnace to a vertical plane passing through the entry region ofthe final heating zone 18. A pair of elongated second channels 60, shownin FIG 3, is fixed to the third I-beams 58 and is coextensive therewith.An elongated refractory block 64 is suitably fixed to the upper surfaceof the second channels 60. Passageways 66, shown in FIG. 3, are formedthrough the refractory block 64 for snugly receiving the vertical legs44 of tubular structure 42. Brackets 68 are suitably fixed between theinner surface of the second channels 60 and the vertical legs 44 forproviding additional support for the tubular structure 42.

As clearly shown in FIGS. 1 and 2, the structural members above secondI-beams 54 are inclined downwardly with respect to the I-beams 54. Thisinclination is provided by suitably varying the height offirst channels56. In addition, the height of vertical legs 44 of tubular structure 42are suitably sized so that both levels of upper section 43 aresubstantially horizontal when support means 30 is in the position shownin FIG. 1. The inclination of members of support means 30 is necessaryfor providing the relationships between the pedestal members 40 and skidsections 34 as shown in FIGs. 1 and 2. These relationships will bebetter understood as the present description continues.

The final heating zone 18 and the excavation 53 are sealed from eachother by well-known seals. As shown schematically in FIG. 4, the sealsinclude a series of suitably supported troughs 70 circumscribing thearea adjacent outer sides and ends of each individual third I-beams 58forming part of an individual upright support structure 50. As shown inFIG. 3, elongated blades 72 and 73 are fixed to the outer side of eachthird I-beam 58 forming part of an individual support structure and areshaped and sized to extend into the channels in between the supportstructures 50 formed by the troughs 70. As shown in FIGS. land 4 blades75 and 76 are fixed to the ends of the third I-beams 58 and are shapedand sized to extend into the opposite end channels formed by troughs 70.A suitable seal level of sealing medium, such as water, for example, ismaintained in the troughs 70 to insure a proper seal between theexcavation 53 and final heating zone 18.

All of the support structures 50 are coupled together by a pair ofelongated transversely extending I-beams 80 suitablyfixed to all of thefirst I-beams 52 forming part of the support structures 50. The entireassembly of pedestal members 40 and support structures 50'is supportedon the floor of excavation 53 by pairs of laterally spaced drive units82 and guide units 84 oppositely longitudinally disposed to each other.Each drive unit 82 includes a hydraulic cylinder 86 connected with asource of hydraulic fluid, not shown. The cylinder 86 is pivotablysupported between a clevis bracket 88 suitably fixed to a base 89resting on the floor of excavation 53. The piston rod 90 of thehydraulic cylinder 86 is pivotably connected with a clevis bracket 92which is suitably fixed with I-beams 80. Each guide unit 84 includes anelongated base member and a pair of longitudinally oppositely disposedidentical rollers 93 supported for rotation by identical clevis brackets94 suitably fixed to the top of base member 95. An arcuately formedguide rail 96 is suitably fixed to second l-beams 54 and is arranged toengage the rollers 93. The guide rails 96 are shaped so that when eachof the hydraulic cylinders 86 is actuated from its retracted state shownin FIG. 1 to extend the piston rod 90 to the position shown in FIG. 2.the assembly of pedestal members 40 and vertical supports 50 will movein an arcuate path towards and upwardly of the discharge end 20 offurnace 10, as it goes from the position shown in FIG. 1 to the positionshown in FIG. 2.

The skid sections 34 and pedestal members 40 are sized so that thehorizontal plane including the upper surfaces of the refractory cap 46is disposed below the horizontal plane including the wear bar 35 whenslabs 11 are being pushed through the furnace chamber. During pushingoperations the wear bar 48 on the first level 43a of the upper portion43 of vertical support 42 will be generally parallel to and below thewear bars on skids 24 in the heating zone 18. When the assembly ofpedestal members 40 and support structures 50 is moved from the positionshown in FIG. 1 to the position shown in FIG. 2, the plane of therefractory caps 46 will be inclined to and above the horizontal plane ofthe wear bars 35 of skid sections 34. Thus, by actuating the assembly tothe position of FIG. 2, the slabs 11 originally on the portions of theskid sections 34 immediately above'the refractory caps 46 will be raisedoff of the skid sections 34 and supported on the refractory caps 46forming part of the pedestal members 40. Therefore, when the slabs 11are at rest (i.e. not being pushed through the furnace), the slabs infinal heating zone 18 are heated while being supported by the pedestalmembers 40. As indicated earlier in this specification, it will takeconsiderably less time, compared to a solid hearth, for removing theskid marks formed on'the slabs by skids 24 and, also, less time forobtaining uniformity of temperature of the slabs before being dischargedfrom furnace 10 to be worked in a subsequent process, such as rolling,for example.

FIG. 5 illustrates another embodiment of the support means 30 formingpart of the present invention. In FIG; 5, all of the structure describedearlier is the same except that the pedestal members 40' are fixed tothe platforms 32 and the skids 24 include upstream sections disposed inthe preheating and heating zones and downstream sections 24b disposed inthe final this embodiment the horizontal plane including the refractorycaps 46 of pedestal members 40' is disposed below the horizontal planeincluding the wear bars 35 of downstream skid sections 24b. Duringpushing of the slabs, the piston rod 90 of the cylinder 86 will be fullyextended in order to maintain relationship of the planes of the pedestalmembers 40' and downstream skid sections 2412, just described. After thecompletion of the pushing operation ofthe slabs 11 in the furnace, thepiston rod 90 of cylinder 86 is retracted and the plane of thedownstream skid sections 24b will then be disposed toward and downwardlyof the discharge end 20 of the furnace l0, and below the horizontalplane ofthe refractory caps 46' of the pedestal members 40'. Thus, whenall the slabs in the furnace are at rest, those slabs in the finalheating zone 18 will be heated while they are supported by pedestals40'.

The advantages of the present invention, i.e., fast elimination of skidmarks from the work pieces, fast-heating time for reaching uniform workpiece temperature, elimination of refractory hearth wear, greatercapacity, and others. were spelled out in the introductory portion ofthis specification. It should be now better appreciated how the furnaceof the present invention provides these aforementioned advantages. Inaddition, it should be noted that the arcuate or rocking" movement givento the slabs in the final heating zone provides an additional advantageto this invention. Each slab being pushed through a heating furnace isin abutment with the slabs adjacent thereto. As a result, it has beenfound-in conventional furnaces that slabs will, on occasion weld to eachother by the time they reach discharge. Welding'generally occurs in thesoaking zone of the conventional furnace. In this invention, therocking-' movement provided by the means described regarding FIGS. 1, 2,3, and 5 will cause the slabs to separate at the entry of the finalheating zone 18 and, therefore, virtually eliminating any weldingofslabs to each other,

FIGS. 6 and 7 illustrate yet another embodiment of this invention. Theembodiment of FIGS. 6 and 7 is essentially the same as that illustratedin FIGS. 1, 2, and 3, except that pedestal members simply tilt upwardlyand downwardly with respect to the skids in the final heating zone. Thefurnace 100 includes downstream skid sections 102, forming part ofelongated water-cooled skids extending throughout the length of thefurnace, suitably supported by platform 104. Elongated pedestal members106 are disposed between the downstream skid section 102, each of whichpedestal members include an upright tubular structure 108 formed in afencelike pattern having a longitudinally extending upper section 110and a plurality of vertical legs 1'12joined to the upper section 110.Circulating cooling water is passed through the tubular structure 108and enters and leaves the structure through the vertical legs 112 by anysuitable piping arrangement well known in the art. An elongatedrefractory cap 114 extends over the top surface of each upper section110 and is suitably fixed thereto by bracket 116. Each pedestal member106 is suitably fixed to an elongated beam 118 extending longitudinallywith respect to the furnace. The beams 118 are fixed to one another bybeams 120 and 122 suitably secured to the respective upstream anddownstream ends of the beams 118. The beams 118, 120 and 122 aredisposed below the final heating zone 124 in an excavation 126 suitablyarranged below the furnace. The pedestal member 106 assembly, includingthe beams 118, 120, and 122, is supported on the floor of excavation 126by pairs -of laterally spaced drive means 130 and guide means 132, op-

positely longitudinally disposed to each other. Each drive unit includesa hydraulic cylinder 134 connected with a source of hydraulic fluid, notshown. The cylinder 134 is pivotably supported between a clevis bracket136 suitably fixed to a base 138 resting on the floor ofexcavation 126.The piston rod 140 of the cylinder 134 is pivotably connected with aclevis bracket 142 which is suitably fixed to beam 122. A clevis plate.144 is suitably fixed to beam 120 and is pivotably connected with plate146 suitably fixed to the top of base 148 resting on the floorofexcavation 126.

The'skid sections 102 and pedestal members 106 are sized so that thehorizontal plane including the upper surfaces of the refractory caps 114is disposed below the horizontal plane including the wear bars ontheskids, including downstream skid sections 102. During pushing operationsthe slabs 150 will move through furnace 100 over the skids. When theslabs 150 come to rest, the cylinders 134 are actuated to extend thepiston rods 140. The pedestal members 106 all tilt upwardly towards thedischarge end of the furnace, as shown in FIG. 7. Thus, the slabs 150 inthe final heating zone 124 which were originally on the upstream skidsections 102 will be raised off of the skid sections and supported onthe refractory caps 114 forming part of pedestal members 106. The pistonrods are retracted to return the pedestal members 106 to the positionshown in FIG. 6.

It should be clear that the furnace of FIGS. 6-8 has essentially thesame advantages as those set forth for the earlier embodiments. Itshould also be noted that the furnace of FIGS. 6- 8'can be adapted sothat the skid sections in the final heating zone 124 are arranged totilt relative to the pedestal members. Such an arrangement would besimilar to the embodiment of the invention illustrated in FIG. 5. Itshould be further noted that the embodiment of this inventionillustrated in FIGS. 6-8 could be simply adapted to a batch heatingfurnace; although it should also be understood that the otherembodiments of this invention can, likewise, be adapted to a batchfurnace. In batch furnaces, however, there would be no need to havewater-cooled skids. The work pieces could be placed on piers, forexample, and then raised onto pedestal members in any of the manners setforth above.

In the embodiments of this invention previously described, the movableobject support members located in the final heating zone were providedwith means to move them in a more or less upwardly and downwardlyslanting relationship with respect to the stationary support members. Irefer to this movement as being along a tiltable path; with theunderstanding, however, that this expression is not limited only totilting as illustrated in FIGS 6, 7, and 8, but to any movement whichresults in one set of support members being inclined with respect toanother set of support members to result in the transferring of objectsbetween the support members to achieve the advantages set forthhereinabove.

While l have shown and described present preferred embodiments of thepresent invention, it is to be distinctly understood that the inventionis not limited thereto but may be otherwise variously embodied withinthe scope of the following claims.

Iclaim:

l. A furnace for heating objects, comprising:

an elongated gener'allyhorizontally oriented hollow housing defining afurnace chamber having first heating zones and a final heating zoneinwardly adjacent the discharge end of the housing;

burners disposed in said housing for supplying hot products ofcombustion into the chamber to apply heat to the ob jects to be heated;

a plurality of elongated transversely spaced skid means supported insaid'housing and extending longitudinally with respect thereto forsupporting objects therein;

a plurality of elongated transversely spaced pedestal means disposedbetween said skid means in said final heating zone and having objectsupporting upper surfaces;

the plane extending transversely of said housing and including the uppersurfaces of said pedestal means is below the plane extendingtransversely of said housing and including the upper surfaces of saidskid means when objects to be heated are being pushed along the skidmeans through the furnace chamber; and

movable frame means for supporting all of one of said means and forselectively tilting such means upwardly and downwardly with respect tothe discharge end of said housing from a first position where the saidplane of said skid means is above said plane of said pedestal means to asecond position where said plane of said skid means is inclined to andbelow said plane of said pedestal means,

whereby objects being pushed in said furnace chamber upwardly anddownwardly with respect to the discharge end of i said housing from afirst position where said plane of said pedestal means is below saidplane of said skid means to a above and inclined upwardly towards saiddischarge end with respect to said plane of said skid means.

3. A furnace as set forth in claim 1 wherein said skid means includefirst skid members disposed in said first heating zones and second skidmembers disposed in said final heating zone and detached from said firstskid members; said frame means supports said second skid members andisselectively tiltable upwardly and downwardly with respect to thedischarge end of said housing from a first position where said plane ofsaid pedestal means is below the plane extending transversely of saidhousing and including the upper surfaces of said second skid members toa second position where said plane of said second skid members is belowand inclined downwardly towards said discharge end with respect to saidplane of said pedestal means.

4. A furnace as set forth in claim 1 wherein saidframe means includes anelongated base means extending generally longitudinally of said housing;guide means operatively arranged atone end portion of said base meansfor guiding said base means along an arcuate upward and downward path;drive means operatively fixed with the other end portion of said basemeans for selectively moving said base means up-' wardly and downwardlyalong said path.

5. A furnace as set forth in claim 1 wherein said frame means includesan elongated base means extending generally longitudinally of saidhousing; guide means operatively arranged atone end portion of said basemeans and including at least one guide rail formed in an arcuate shapedefining an upward and downward path for said base means and at leastone roller in engagement with said guide rail; and extensible andretractable drive means fixed with the other end portion of said basemeans for selectively moving said base means upwardly and downwardlyalong said path.

6. A furnace as set forth in claim 1 including sealing means betweensaid housing and said frame means for sealing the furnace chamber abovesaid frame means from the area below said frame means.

7. A furnace as set forth in claim 1 wherein said frame means includes aplurality of elongated transversely spaced beams extending generallylongitudinally of said housing; attachment means fixed between saidbeams for attaching the sequentially spaced beams to each other; anelongated upwardly extending post means fixed to each of said beams anddisposed in the area of said final heating zone for supporting one each'of said pedestal means in an upright position such that said plane ofsaid pedestal means is below said plane of said skid means; at least oneroller supported below said housing and disposed below one of said beamsat one end portion thereof; a guide rail fixed to one of said beams andin engagement with said roller, and formed in an arcuate shape toprovide said beams with a'path of movement towards and upwards of thedischarge end of said housing and away and downwards of the dischargeend of said housing, and extensible and retractable drive means fixed toone of said beams at the other end thereof for selectively moving saidbeams along said path.

8. A furnace as set forth in claim 3 wherein said frame means includes aplurality of elongated transversely spaced beams extending generallylongitudinally of said housing; attachment means fixed between saidbeams for attaching the sequentially spaced beams to each other; supportmeans on each ofsaid beams for supporting one each of said second skidmembers in an upright position; said pedestal means is fixed withrespect to said housing; at least one roller supported below saidhousing and disposed below one of said beams at one end portion thereof;a guide rail fixed to one ofsaid beams and in engagement with saidroller and formed in an arcuate shape to provide said beams with atilting path of movement towards and upwards of the discharge end ofsaid housing and away and downwards of the discharge end of saidhousing; and extensible and retractable drive means fixed to one of saidbeams at the other end thereof for selectively moving said beams alongsaid path.

9. A furnace as set forth in claim 1 wherein said frame means includesan elongated base means extending generally longitudinally of saidhousing; guide means operatively arranged atone end portion of said basemeans and including at least one first plate member supported below saidbase means and a second plate member fixed to said base means andpivotably connected with said first plate member; and drive meansoperatively fixed with the other end portion of said base means forselectively tilting said base means upwardly and downwardly.

10. A furnace for heating objects, comprising:

anelongated generally horizontally oriented hollow housing defining afurnace chamber;

burners for supplying hot products of combustion into the furnacechamber to apply heat to the objects to be heated;

a plurality of elongated transversely spaced object support meanssupported in said housing for supporting objects during heating;

said object support means having first members for supporting objects,and second members disposed between said first members, with saidmembers being tiltable upwardly and downwardly with respect to eachother; and

movable frame means operatively arranged with said object support meansfor selectively tilting said members with respect to each other totransfer objects between said members.

11. A furnace as set forth in claim 10 wherein said frame means includesguide means for guiding said frame means in an upwardly and downwardlyarcuate path with respect to one end ofsaid housing.

12. A furnace as set forth in claim 10- wherein said first members ofsaid object support meansincludes a plurality of water-cooled skids;said skids having an upstream first section and a downstream secondsection; said second members are a plurality of pedestals disposedbetween said second section of said skids and having object bearingupper surfaces; said housing has a charge end and a discharge end; saidframe means supports said pedestals and is selectively tiltable upwardlyand downwardly with respect to the discharge end of said housing from afirst position where the plane of the upper surfaces of said pedestalsis below the plane of the second section of said skids to a secondposition where said plane of said pedestals is above and inclinedupwardly towards said discharge end with respect to said plane of saidsecond section of said skids 13. A furnace as set forth in claim 10wherein said first members of said object support means includes aplurality of water-cooled upstream first skids; and a plurality ofwatercooled downstream second skids; said second members are a pluralityof pedestals disposed between said second skids and having objectbearing upper surfaces; said housing has a charge end and a dischargeend; said frame means supports said second skids and is selectivelytiltable upwardly and downwardly with respect to the discharge end ofsaid housing from a first position where the plane of the upper surfacesof said pedestals is below the plane of the second skids to a secondposition where said plane of said second skids is below and inclineddownwardly towards said discharge end with respect to said plane of saidpedestals.

